Support for adjustable lighting fixtures



Jan. 11, 1949. wlEDENHOEFT I 2,458,967 I SUPPORT FOR ADJUSTABLE LIGHTING FIXTURES Filed m. 24, 1944' 2 Sheets-Sheet 1 Jan. 11; 1949. A, wlEDENHOEFT 2,458,967

SUPPORT FOR ADJUSTABLE LIGHTING FIXTURES Filed 001;. 24, 1944 2 Shee ts-Sheet 2 of a table or desk;

'base of the fixture;

f Fig. 3 is an exploded view of the parts shown in 2;

in Figure 8.

Patented Jan. 11, 1949 mm yomc SUPPORT FdBIADJUSTABLE LIGHTING.

FIXTURES Arthur E. Wiedenhoeft, Chicago,-1ll., assignor, by p mesne assignments, to Mitchell Manufacturing Company,-a corporation of Delaware 7 Application October '24, 1944, Serial No. 561L114" This invention relates in fixture having a fixed support or base with' a lamp reflector supported by movable connected arms so that the lamp or reflector may bemoved or adjusted into any desired or suitable position. b

' An important object of the invention is to provide a multiple arm supported fixture withjoint connections having a limited universal movement'.

'A further object of the invention is to provide an arm supported fixture with frictional connec -tions which maybe adjusted depending uponthe Weight of the arms, lamps or reflectors to be supported.

A still further object of the invention is to provide a new and improved joint connection between the supporting arms of an adjustable lighting fixture.

Still another object of the invention is to provide a joint connection for connected arms of an electric lighting fixture in which the electrical connectors cannot become twisted or broken. j

A still further object of the invention is to provide a joint connection for the arms of an adjustable lighting fixture in which the normally exposed joint and connection is covered or enclosed on opposite sides of the joint byeasily' removed covers.

Other and further objects of the invention will appear in the specification and will be apparent from the accompanying drawings in which Fig. 1 illustrates an electric fixture in accordance with this invention as applied to the edge Fig. 2 is a sectional view of the joint at the Fig. 4 .is a view of one side of the joint shown in Fig. 2 with the cover plate removed;

Fig. 5 is a view of the other slde of the joint of Fig. 2 with the cover removed;

cle arness;

Fig. 8 is an elevation of one of the parts shown in Fig. '7;

Fig. 9 is a bottom plan view of the part shown.

Adjustable fixtures for drawing, reading, and

other purposes have heretofore had. arms con- 3 Claims ((11,248-276) general to a lighting nected by joints withmanually adjustable screws for tighteningand loosening the connections.

The present invention substitutes a frictional joint adjustedfor the weight of the fixture so that the arms-and connections maybe se'tat diiferent desired angles to bring the lamp and reflector into any desired position by simply moving the arms or parts with'respects to each other, andthe joint friction being such that it will. hold the parts in any set position without manual loosening and tightening of each joint as the adjustment is made. This requires that the frictional engagement be" adjustable, easily accessible, and for the best wearing qualities that there be no metal or metal contact between the movable parts.

Referring now more particularlyto the drawings, this invention is described as applied to a clamped support type of base as applied to the edge of a table 12 or any other suitable support. The-clamp may comprise'a yoke l3 having an posite side'of the table through which a threaded stem I6 is inserted, having a contact piece I! to engage the under side of the table and a hand nut' I'G' for operating the threaded stem.

. In the upper and lower extensions 14 and I5 are corresponding openings for receiving a hollow. pipe or stem I8 held adjustably in place by thumb screw l9 extending through the connecting portion of the yoke 13.

. A rotary frictional joint is applied directly to the upper. end of. the stem I8 and comprises two opposite circular metal plates 20 and 2| with a ring 22 of frictional material such as fiber, or the like,interposed between them. One of the plates 20'has an offset threaded sleeve 23 for receiving thestem II! with an opening 26 leading to one side of the plate and the other plate 2| has a corresponding threaded sleeve 24 offset with respect to the plate with an opening 2 5 leading to one side of the plate, the opposite side, the opposite side as related" to the two .plates 20'and 2| "when they are placed together.

As shown more clearly inFig. 3, the plate 20 has an inner projection 21 adapted to fit into a circular recess 28 of the other plate 2! with the ring 22 of frictionalmaterial disposedbetween them- At the center of the plate 20 is a perforation 29 sufliciently large for an insulated conductorwire or wires 30 to be'inserted theretl'irough and surrounding this central opening are 'a'number of holes 3! for receiving fastening bolts 32 whlch extend through corresponding holes 33 3 in a friction disc 34, larger. in diameter than the opening 28 in the plate 2!. Washers 35 are inserted below the heads of the fastening screws or bolts 32 bearing against the disc 34 and nuts 36 are threaded on the other ends of the bolts after first interposing spring washers 31 between the nutsand the adjacent surface of'the plate 20.

With this construction, a conductor or conductors is threaded in through the sleeve 23 of one plate, thence through the central opening 29 to the opposite side of the other plate 2i, and

thence outwardly through the opening 25 and through the sleeve 24.

With this construction, the conductor wire or wires do not become twistedfknotted, or broken, because the plate does not have a complete rotary motion with respect to eachother.

The height of the projection 21 is less than the combined height of the friction ring 22 and the plate 2! so that the disc 34 bears against the adjacent surface of the plate 2| and compresses the ring 22 between the plates, thus avoiding a metal to metal contact between the plates. In order to increase or decrease the frictional resistance between the plates, it is therefore necessary only to tighten or loosen the fastening bolts or screws 32- with respect to their nuts 36.

Both of the plates 28 and 2! are formed with outwardly extending marginal rims .38 extending relatively in opposite directions when the plates are secured together and each forming a seat for an opposite decorative cover 39 which has a central opening. .40 for receiving a fastening bolt 4| inserted therethrough and through the central opening 29 of plate 20 with a cap nut 42 threaded on the other end of the bolt outside of the opposite plate and. holding them together. This bolt is sufficiently, small so that it does not obstruct the opening 2.9 forthe passage conductors 30 therethrough.

Another similar frictional device is connected at the ends of tubular pipes 43 and 44 threaded into the respective sleeves 213 and 24 and a similar frictional device as shown more clearly in Figs. 6 to 9 is formed with a sleeve 45. at right angles to the opposite sleeve 23 so that a hollow stud 46 may be inserted into thesleeve 45 at one side, abutting a shoulder 4'! at the bottom and having a, threaded stem 48 extending through a. hole 49 in the bottom of the sleeve. This stud is held tightly in the sleeve by a spring washer 50 and a frictional washer interposed between the bottom of the sleeve 45 and-a fastening nut 52 threaded on the stem .48. :The hollow. stud has an opening 53 at one side and extending partially around it so that the. conductor wire 30 will extend freely in the stud without twisting or bending the wire since the. stud is limited to a rotation of less than 180 by an elbow. 54 which extends laterally therefrom'to provide means for attachment of a tubular connection 55. Thus the stud may be rotated by the frictional joint in I either direction above .or below the joint as "represented in Fig. 7, and the stud itself maybe rotated about an axis at right angles to the axis of rotation of the frictional joint. Thus if a refiector 56 is connected to the tubularconnection 55, it may be moved upon two axes at right angles to each other for adjusting the position thereof at any desired angle and thus constitutof the fixture, but also to hold the parts in any ing a substantially universal movement, and in addition, the pipes or conduits 43 and 44 may be moved to raise or lower the fixture or. to vary I the position of the parts as indicated by the also be moved about the axis of the pipe l8 by adjusting the thumbscrew l9, and if more adjustment and movement is desired, another frictional joint having a stud connection at right angles thereto may be substituted for the frictional joint connecting the pipes 43 and 44. Similarly another frictionaljoint of the. type shown in Fig. '7 may be added to the combination as shown in Fig. 1 by adding another tubular pipe similar to 43 or 44.

With thisconstruction, it is apparent that a lighting fixture having universal adjustment is provided in which the frictional joints are adjustable to carrythe weight not only of a lamp in the reflector, the reflector itself and the parts position in which they are set, thus making it unnecessary to manually adjust the friction between the separate pipes in setting up the fixture, and at the same time providing means for varying this friction at the joints if they should become worn or if the weight of the lamp, reflectoror other parts is changed.

This construction also prevents damage to the conductor wire or wires, since they are so disposed within and through the joint that they do not become twisted, knotted, or broken because of the movement of the parts. All objectionable features of the connections are encased or enclosed in the covers which add adeoorative efiect to the joints and to the fixture itself.

Various other changes in .the construction, combination, and arrangement of the parts may be made without departing from the spirit and ether, friction discs disposed between the plates,

and between said plates and said clamping means, for varying frictional engagement of the plates, depending upon the load which they are to carry, and the plates being rotatable without twistingthe wires enclosed in the joint cover plates receivable into recesses in the rotatable plates, and suitable clampin means for holding cover plates in place.

2. In a lighting fixture of the enclosed Wire frictional adjustment type, a rotatable frictional joint comprising a pair of rotatable plates, each having a threaded sleeve extending therefrom and an opening fromthe sleeve to one side of the plate, one plate having a projection and the other plate having an opening through which the projection extends, a frictional ring interposed between the plates outside of the projection, a plurality of clamping bolts extending through the projection of. one of the plates and having a clamping disc for engaging the other plate and holding it against the frictional ring, the plates and disc having central openings through which the" wires extend without twisting when the joint is turned, and a spring washer and a tightening nut on each of the bolts at the side of the other plate for varying the tension between the plates.

3. In a lighting fixture of the enclosed wire 5 6 frictionally adjustable type, a rotary frictional UNITED STATES PATENTS joint comprising a pair of plates having a common center upon which they are rotatable, a fric- Number m Date tional ring inserted between the plates, means 320,941 Macomber J1me 1385 for adjustably clamping the plates together, and 5 454,553 fi J1me 1391 the pla es having an unobstructed center open- ,036,676 Miller Aug. 27, 1912 ing t ough which the wires extend and outer 1, 6, 7 Ellis Dec. 10, 1912 marginal rims, a pair of cover plates inserted in 1,693,925 H0111 1923 the rims, and a fastening screw for the cover 1,357,347 Heinemam'l y 1932 plates inserted through them and through the 10 2,116,050 stock et y 1938 central opening of the plates. ,200,518 Perbal l May 14, 1940 ARTHUR WIEDENHOEFT' 2233,300 Trythall Feb. 25, 1941 REFERENCES CITED The following references are of record in the 15 file of this patent: 

